Suppression of cavitation inception by gas bubble injection; A Numerical study focusing on bubble-bubble interaction

Ida, Masato; Naoe, Takashi   ; Futakawa, Masatoshi  

The dynamic behavior of cavitation and gas bubbles under negative pressure has been studied numerically to evaluate the effect of gas bubble injection on the suppression of cavitation inception. In our previous studies it has been demonstrated by direct observation that cavitation occurs in liquid mercury when mechanical impacts are imposed and it will cause cavitation damage in spallation neutron sources. In the present paper, we have performed numerical investigations on the dynamics of cavitation bubbles in liquid mercury using a multibubble model that takes into account the interaction of a cavitation bubble with preexisting gas bubbles through the bubble-radiated pressure waves. The numerical results suggest that cavitation inception is suppressed by the positive pressure wave radiated by the injected large gas bubbles which decreases the magnitude of the negative pressure in the mercury.